The present invention relates generally to the field of medical diagnostic systems, such as imaging systems. More particularly, the invention relates to a system and technique for ultrasound color flow Doppler imaging of fluid flow fields.
Ultrasonic scanners for detecting blood flow based on the Doppler effect are known. Such systems operate by actuating an ultrasonic transducer array to transmit ultrasonic waves into the object and receiving ultrasonic echoes backscattered from the object. In the measurement of blood flow characteristics, returning ultrasonic waves are compared to a frequency reference to determine the frequency shift imparted to the returning waves by flowing scatterers such as blood cells. This frequency, i.e., phase shift, translates into the velocity of the blood flow. The blood velocity is calculated by measuring the phase shift from firing to firing at a specific range gate.
The change or shift in backscattered frequency increases when blood flows toward the transducer and decreases when blood flows away from the transducer. Color flow images are produced by superimposing a color image of the velocity of moving material, such as blood, over a black and white anatomical B-mode image. Typically, color flow mode displays hundreds of adjacent sample volumes simultaneously, all laid over a B-mode image and color-coded to represent each sample volume""s velocity.
Typically, color flow processors estimate blood flow velocity, blood flow power, and blood flow variance. Typically, color flow data is used to modify the color of a region of interest on a display screen. The user selects the type of data used for the display. The modes typically available are power only, velocity only or velocity and variance combined.
In current ultrasound scanners, various color flow display parameters are either fixed with no user selectability or are preset to some specific setting and can only be changed if action is taken by the user, one parameter at a time. This limits image quality and user productivity for any given application and scanning situation. There is a need for a scanner in which these same parameters can all be automatically adjusted at the same time to optimize image quality related to color flow display for a specific scanning situation, thus increasing user productivity.
In the color flow power mode of operation, known ultrasound scanners typically provide a color flow dynamic range based on a compression curve preselected at the factory depending on the type of scanning application. For example, one dynamic range based on one compression curve is selected for scanning of the kidney, whereas another dynamic range based on another compression curve is selected for scanning of the carotid artery. Frequently, the actual scan data has a dynamic range different from the range upon which the compression curve is based. As a result, the dynamic range of the display is less than optimal. Accordingly, there is a need for a color flow ultrasound scanner which can automatically adjust for changes in the dynamic range of the received signals.
Solutions to the problems described above have not heretofore included significant remote capabilities. In particular, communication networks, such as, the Internet or private networks, have not been used to provide remote services to such medical diagnostic systems. The advantages of remote services, such as, remote monitoring, remote system control, immediate file access from remote locations, remote file storage and archiving, remote resource pooling, remote recording, remote diagnostics, and remote high speed computations have not heretofore been employed to solve the problems discussed above.
Thus, there is a need for a medical diagnostic system which provides for the advantages of remote services and addresses the problems described above. In particular, there is a need for remote upgrades, remote diagnostics, remote servicing, remote viewing, remote file storage, remote control, and remote adjustments to system parameters and functions. Furthermore, there is a need for contractual arrangements, such as, per use licenses which lease the medical diagnostic equipment based on use. Additionally, remote services may include expert on-line assistance for image scanning techniques, image analysis, pathology detection, imaging unit maintenance, and other expert-aided operations.
One embodiment of the invention relates to an apparatus for displaying images in response to color flow signals in an ultrasound imaging system which generates color flow signals in response to ultrasound signals backscattered from a subject under study. The apparatus includes a memory connected to store first memory values in response to the color flow signals; a logic unit connected to determine a dynamic range compression scheme based on an analysis of the first memory values and to generate second memory values based on the dynamic range compression scheme; a display connected to display a color flow image in response to the second memory values; and a network connectivity module coupled to the system to provide communication with a remote facility over a network, the remote facility providing remote services.
Another embodiment of the invention relates to an improved method for displaying images in response to the color flow signals in an ultrasound imaging system which generates color flow signals in response to ultrasound signals backscattered from a subject under study. The method includes storing first memory values in response to the color flow signals; determining a dynamic range compression scheme based on an analysis of the first memory values; generating second memory values based on the dynamic range compression scheme; displaying a color flow image in response to the second memory values; and communicating the color flow image or data associated with the image to a remote facility, the remote facility providing remote services over a network.
Other principle features and advantages of the present invention will become apparent to those skilled in the art upon review of the following drawings, the detailed description, and the appended claims.